Potential energy curves of the quasi-stable states of CO²⁺ determined using Auger spectroscopy

Observations of Auger transitions to quasi-stable states of CO²⁺ subsequent to C 1s^-1 and O 1s^-1 ionizations of CO are presented along with the corresponding photoelectron spectra and calculations of the potential energy curves. The equilibrium distances R_e, the vibrational energies ℏω, and the anharmoncities xℏω, for the final states a¹Σ⁺, b¹Π, A³Σ⁺, and d¹Σ⁺ are derived from fits to the spectra by assuming Morse potentials. A comparison of these Morse potentials with theoretical potential energy curves reveals excellent agreement in the Franck-Condon regions of the Auger transitions. The relative intensities for the observed C 1s^-1 and O 1s^-1 Auger transitions are also derived.